Compounds and liquid-crystalline medium

Abstract

The invention relates to compounds of the formula I, and to a liquid-crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises one or more compounds of formula I, defined herein, for use in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect, and to the use of the compounds of the formula I for the stabilization of a liquid-crystalline medium which comprises one or more compounds of the formula II and one or more compounds of the formulae III-1 to III-4, defined herein.

Claims

1. A liquid-crystalline medium comprising: a) one or more compounds of formula I ##STR00216## in which n denotes 3 or 4, m denotes (4n), ##STR00217## denotes an organic radical having 4 bonding sites, Z.sup.11 and Z.sup.12, independently of one another, denote O, (CO), (NR.sup.14) or a single bond, but do not both simultaneously denote O, r and s, independently of one another, denote 0 or 1, Y.sup.11 to Y.sup.14 each, independently of one another, denote alkyl having 1 to 4 C atoms, or alternatively, independently from each other, the two pairs (Y.sup.11 and Y.sup.12) and (Y.sup.13 and Y.sup.14) may be connected by a bond to form together a divalent group having 3 to 6 C-atoms, R.sup.11 in each case, denotes O.sup., R.sup.12 on each occurrence, independently of one another, denotes H, F, OR.sup.14, NR.sup.14R.sup.15, a straight-chain or branched alkyl chain having 1-20 C atoms, in which one CH.sub.2 group or a plurality of CH.sub.2 groups may each be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, or denotes a hydrocarbon radical which contains a cycloalkyl or alkylcycloalkyl unit, and in which one CH.sub.2 group or a plurality of CH.sub.2 groups may each be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and in which one H atom or a plurality of H atoms may each be replaced by OR.sup.14, N(R.sup.14)(R.sup.15) or R.sup.16, or denotes an aromatic or heteroaromatic hydrocarbon radical, in which one H atom or a plurality of H atoms may each be replaced by OR.sup.14, N(R.sup.14)(R.sup.15) or R.sup.16, R.sup.13 on each occurrence, independently of one another, denotes a straight-chain or branched alkyl chain having 1-20 C atoms, in which one CH.sub.2 group or a plurality of CH.sub.2 groups may each be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, or denotes a hydrocarbon radical which contains a cycloalkyl or alkylcycloalkyl unit, and in which one CH.sub.2 group or a plurality of CH.sub.2 groups may each be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and in which one H atom or a plurality of H atoms may each be replaced by OR.sup.14, N(R.sup.14)(R.sup.15) or R.sup.16, denotes an aromatic or heteroaromatic hydrocarbon radical, in which one H atom or a plurality of H atoms may each be replaced by OR.sup.14, N(R.sup.14)(R.sup.15) or R.sup.16, or can be ##STR00218## (1,4-cyclohexyl), in which one or more CH.sub.2 groups may each be replaced by O, CO or NR.sup.14, or an acetophenyl, isopropyl or 3-heptyl radical, R.sup.14 on each occurrence, independently of one another, denotes a straight-chain or branched alkyl or acyl group having 1 to 10 C atoms or an aromatic hydrocarbon or carboxyl radical having 6-12 C atoms, R.sup.15 on each occurrence, independently of one another, denotes a straight-chain or branched alkyl or acyl group having 1 to 10 C atoms or an aromatic hydrocarbon or carboxyl radical having 6-12 C atoms, R.sup.16 on each occurrence, independently of one another, denotes a straight-chain or branched alkyl group having 1 to 10 C atoms, in which one CH.sub.2 group or a plurality of CH.sub.2 groups may each be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and b) one or more compounds of formula II ##STR00219## in which R.sup.21 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, and R.sup.22 denotes an unsubstituted alkenyl radical having 2 to 7 C atoms, and optionally c) one or more compounds selected from formulae III-1 to III-4, ##STR00220## in which R.sup.31 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, R.sup.32 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms, and m, n and o each, independently of one another, denote 0 or 1.

2. The medium according to claim 1, wherein said medium contains one or more compounds selected from formulae III-1 to III-4.

3. The medium according to claim 1, wherein the total concentration of the compounds of the formula I in the medium as a whole is 1 ppm or more to 1,000 ppm or less.

4. The medium according to claim 1, wherein said medium comprises a compound of the formula II in which R.sup.21 denotes n-propyl and R.sup.22 denotes vinyl.

5. The medium according to claim 4, wherein the total concentration of the compounds of the formula II in the medium as a whole is 25% or more to 45% or less.

6. The medium according to claim 1, wherein said medium comprises one or more compounds of formula III-2-2 ##STR00221## in which R.sup.31 and R.sup.32 have the respective meanings given under formula III-2 in claim 1.

7. The medium according to claim 1, wherein said medium comprises one or more compounds of formula III-4.

8. The medium according to claim 1, wherein said medium additionally comprises one or more chiral compounds.

9. An electro-optical display or electro-optical component, comprising a liquid-crystalline medium according to claim 1.

10. The display according to claim 9, wherein said display is based on the VA or ECB effect.

11. The display according to claim 9, wherein said display comprises an active-matrix addressing device.

12. A method of generating an electro-optical effect comprising applying a voltage to a liquid-crystalline medium according to claim 1.

13. A method according to claim 12, wherein said liquid-crystalline medium is in an electro-optical display or in an electro-optical component.

14. A process for the preparation of a liquid-crystalline medium according to claim 1, said process comprising: mixing one or more compounds of formula I, with one or more compounds of formula II, and optionally one or more compounds selected from formulae III-1 to III-4.

15. A liquid-crystalline medium according to claim 1, wherein said medium further comprises one or more compounds selected from formulae OH-1 to OH-6 ##STR00222##

16. A liquid-crystalline medium according to claim 1, wherein ZG denotes ##STR00223##

17. A compound selected from formulae I-1b-1 and I-1b-2, ##STR00224##

18. A compound selected from formulae I-1c-1 and I-1c-2, ##STR00225##

19. A compound selected from the following formulae: ##STR00226##

20. The liquid crystal medium according to claim 16, wherein ZG denotes ##STR00227##

21. The liquid crystal medium according to claim 1, wherein, in formula I, n is 3.

22. The liquid crystal medium according to claim 1, wherein, in formula I, n is 4.

23. The liquid crystal medium according to claim 21, wherein said one or more compounds of formula I is a compound of formula 1-7a-1 ##STR00228##

24. The liquid-crystalline medium according to claim 1, wherein ZG denotes >CH[CH.sub.2].sub.pCH.sub.2 or >CH[CH.sub.2].sub.pCH<, and p is an integer from 0 to 16.

25. The liquid-crystalline medium according to claim 24, wherein ZG denotes >CH[CH.sub.2].sub.pCH<, and p is an integer from 0 to 16.

26. The liquid crystal medium according to claim 22, wherein said one or more compounds of formula I is a compound of formula I-8a-1 ##STR00229##

Description

EXAMPLES

(1) The following examples explain the present invention without restricting it in any way. However, the physical properties make it clear to the person skilled in the art what properties can be achieved and in what ranges they can be modified. In particular, the combination of the various properties which can preferably be achieved is thus well defined for the person skilled in the art.

Substance Examples

(2) The following substances are preferred substances of the formula I in accordance with the present application or substances of the formula I preferably to be employed in accordance with the present application.

(3) ##STR00195## ##STR00196## ##STR00197## ##STR00198## ##STR00199## ##STR00200## ##STR00201##

Synthesis Example 1

Synthesis of bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N-dioxyl succinate (Substance Example 1)

(4) ##STR00202##

(5) 2.15 g (12.26 mmol) of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, 40 mg (0.33 mmol) of 4-(dimethylamino)pyridine and 1 ml (12.4 mmol) of dried pyridine are initially introduced in 20 ml of dry dichloromethane. 4 ngstrm activated molecular sieve is subsequently added, and the mixture is stirred at room temperature (RT for short; about 22 C.) for 90 min. The reaction solution is cooled to a temperature in the range from 7 to 10 C., and 0.71 ml (6.13 mmol) of succinyl dichloride is slowly added, and the mixture is stirred at RT for 18 h. Sufficient sat. NaHCO.sub.3 solution and dichloromethane are added to the reaction solution, and the organic phase is separated off, washed with water and sat. NaCl solution, dried over Na.sub.2SO.sub.4, filtered and evaporated. The crude product is purified over silica gel with dichloromethane/methyl tert-butyl ether (95:5), giving the product as a white solid having a purity of >99.5%.

Synthesis Example 2

Synthesis of bis(2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl) decanedioate (Substance Example 4)

(6) ##STR00203##

(7) 28.5 g (166 mmol) of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (free radical) and 250 mg (2.05 mmol) of 4-(dimethylamino)pyridine are dissolved in 300 ml of degassed dichloromethane, and 50.0 ml (361 mmol) of triethylamine are added. The mixture is subsequently degassed and cooled to 0 C., and 10 g (41.4 mmol) of sebacoyl chloride dissolved in 100 ml of degassed dichloromethane are added dropwise at 0-5 C., and the mixture is stirred at room temperature for 18 h. When the reaction is complete, water and HCl (pH=4-5) are added with ice-cooling, and the mixture is stirred for a further 30 min. The organic phase is separated off, and the water phase is subsequently extracted with dichloromethane, and the combined phases are washed with saturated NaCl solution and dried over Na.sub.2SO.sub.4, filtered and evaporated, giving 24.4 g of a red liquid, which together are passed through 100 g of basic Al.sub.2O.sub.3 and 500 g of silica gel on a frit with dichloromethane/methyl tert-butyl ether (95/5), giving orange crystals, which are dissolved in degassed acetonitrile at 50 C. and crystallized at 25 C., giving the product as orange crystals having an HPLC purity of 99.9%.

Synthesis Example 3

Synthesis of bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N-dioxylbutanediol (Substance Example 7)

(8) ##STR00204##

(9) Sufficient pentane is added to 15.0 g (60% in mineral oil, 375 mmol) of NaH under a protective gas, and the mixture is allowed to settle. The pentane supernatant is pipetted off and carefully quenched with isopropanol with cooling. 100 ml of THF are then carefully added to the washed NaH. The reaction mixture is heated to 55 C., and a solution of 50.0 g (284 mmol) of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl in 400 ml of THF is carefully added dropwise. The hydrogen formed is discharged directly. When the addition of the solution is complete, stirring is continued at 60 C. overnight (16 h). The reaction mixture is subsequently cooled to 5 C., and 1,4-butanediol dimethylsulfonate is added in portions. The mixture is subsequently slowly heated to 60 C. and stirred at this temperature for 16 h. When the reaction is complete, the mixture is cooled to RT, and 200 ml of 6% ammonia solution in water are added with cooling, and the mixture is stirred for 1 h. The organic phase is subsequently separated off, the aqueous phase is rinsed with methyl tert-butyl ether, the combined organic phases are washed with sat. NaCl solution, dried and evaporated. The crude product is purified over silica gel with dichloromethane/methyl tert-butyl ether (8:2) and crystallized from acetonitrile at 20 C., giving the product as a pink crystalline solid having a purity of >99.5%.

Synthesis Example 4

Synthesis of bis[2,2,6,6-tetramethyl-1-(1-phenyl-ethoxy)piperidin-4-yl]succinate (Substance Example 24)

(10) ##STR00205##

Step 4.1: Synthesis of 2,2,6,6-tetramethyl-1-(1-phenylethoxy)piperidin-4-ol

(11) ##STR00206##

(12) 5.0 g (29.03 mmol) of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, 7.80 g (58.1 mmol) of 2-phenylpropionaldehyde and 100.6 mg (1.02 mmol) of copper(I) chloride are initially introduced in 20 ml of tert-butanol. 6.45 ml (58.06 mmol) of 35% hydrogen peroxide solution are then carefully and slowly added dropwise at such a rate that the internal temperature does not exceed 30 C. The mixture is therefore cooled by means of ice-cooling during the dropwise addition. Oxygen is formed in the reaction and would spontaneously be released in large quantities if the addition were too fast and the temperature too high. When the addition is complete, the reaction solution is stirred at RT for a further 16 h, and sufficient water/methyl tert-butyl ether is subsequently added, and the organic phase is separated off. The organic phase is washed with 10% ascorbic acid until peroxide-free, and the peroxide content is checked. The mixture is subsequently washed with 10% NaOH solution, water and sat. NaCl solution, dried over Na.sub.2SO.sub.4, filtered and evaporated. The crude product obtained is purified over silica gel with heptane/methyl tert-butyl ether (1:1), giving the product as colorless crystals.

Step 4.2: Synthesis of bis[2,2,6,6-tetramethyl-1-(1-phenylethoxyl)piperidin-4-yl]succinate

(13) 1.52 g (5.5 mmol) of the product from the preceding step, the compound 2,2,6,6-tetramethyl-1-(1-phenylethoxyl)piperidin-4-ol, 15.3 mg (0.125 mmol) of dimethylaminopyridine and 1.02 ml (12.6 mmol) of dried pyridine are initially introduced in 10 ml of dichloromethane and cooled to a temperature in the range from 7 to 10 C. 0.255 ml (2.199 mmol) of succinoyl dichloride is then added dropwise as such and if necessary topped up if hydroxyl compound is still present. When the reaction is complete, the reaction mixture is filtered directly through silica gel with dichloromethane and subsequently eluted with heptane/methyl tert-butyl ether (1:1) and pure methyl tert-butyl ether. The product obtained is dissolved in acetonitrile and purified by means of preparative HPLC (2 Chromolith columns with 50 ml/min of acetonitrile), giving the product as a yellow oil having a purity of >99.9%.

Synthesis Example 5

Synthesis of 2,2,6,6-tetramethyl-1-(1-phenyl-ethoxy)piperidin-4-yl pentanoate (Substance Example 31)

(14) ##STR00207##

(15) 2.5 g (9.01 mmol) of the compound 2,2,6,6-tetramethyl-1-(1-phenylethoxy)piperidin-4-ol from step 3.1 and 55.1 mg (0.45 mmol) of (4-dimethylaminopyridine) are dissolved in 50.0 ml of dry dichloromethane and cooled to 3 C. 5.47 ml (27.03 mmol) of valeric anhydride are added at this temperature, and the mixture is stirred at room temperature for 14 h. When the reaction is complete, the mixture is carefully poured into ice-water, adjusted to pH 6 using 2N HCl, and the organic phase is separated off. The aqueous phase is extracted with dichloromethane, and the combined organic phases are washed with saturated NaCl solution, a mixture of water and triethylamine (300:50 ml) and dried over MgSO.sub.4, filtered and evaporated. Purification on silica gel with heptane/methyl tert-butyl ether (9:1) gives the product as a colorless oil.

Synthesis Example 6

Synthesis of 1,4-bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) butanedioate (Substance Example 49)

(16) ##STR00208##

(17) 40 ml of water and 80 ml of dioxane are mixed and carefully degassed by means of a stream of argon. 2.0 g (4.7 mmol) of the free radical from Substance Example 1 (Synthesis Example 1) are dissolved in the solvent mixture, and 4.95 g (28.1 mmol) of ascorbic acid are added in portions. The reaction mixture becomes colorless during this addition and is stirred at 40 C. for 18 h under a protective-gas atmosphere. The mixture is cooled to room temperature, and 100 ml of water are added, the mixture is stirred briefly, and the crystals formed are filtered off with suction. The crystals are dissolved in 50 ml of hot degassed THF, and the insoluble constituents are filtered off, and the filtrate is crystallized at 25 C. The pale-pink crystals are then washed by stirring in acetonitrile at room temperature for 18 h, giving the product as pale-pink crystals having an HPLC purity of 100%.

Synthesis Example 8

Synthesis of 1,10-bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) decanedioate (Substance Example 50)

(18) ##STR00209##

(19) All solvents used are thoroughly degassed in advance by means of a stream of argon. During work-up, brown glass equipment must be used. 1.70 g (3.32 mmol) of the free radical from Substance Example 4 (Synthesis Example 2) are dissolved in 60 ml of dioxane. 3.6 g (20 mmol) of ascorbic acid dissolved in 30 ml of water are subsequently added dropwise to the solution at room temperature. The reaction solution starts to become colorless during this dropwise addition, and the reaction is complete after stirring at room temperature for 1 h. The mixture is extracted with 100 ml of dichloromethane, and the organic phase is washed with water, dried over Na.sub.2SO.sub.4, filtered and evaporated. The yellow crystals formed are dried at 160 C. and 10.sup.2 mbar for 5 min, giving a viscous, slowly crystallizing oil.

(20) Liquid-crystal mixtures having the compositions and properties as indicated in the following tables are prepared and investigated.

Examples 1.1 and 1.2 (B1.1 and B1.2) and Comparative Examples 1.0 and 1.1 (C1.0 and C1.1)

(21) The following mixture (M-1), which comprises in total slightly more than 40% of compounds containing an alkenyl end group and 8% of a compound containing a cyclohexenylene unit, is prepared and investigated.

(22) TABLE-US-00009 Mixture M-1 Composition Compound Concentration No. Abbreviation /% by weight 1 CY-3-O2 15.0 2 CY-5-O2 6.0 3 CCY-3-O2 3.0 4 CLY-3-O2 8.0 5 CPY-2-O2 8.0 6 CPY-3-O2 8.0 7 PYP-2-3 11.5 8 CC-3-V 35.0 9 CCP-V-1 5.5 100.0 Physical properties T(N, I) = 75.4 C. n.sub.e(20 C., 589 nm) = 1.5933 n(20 C., 589 nm) = 0.1077 .sub.(20, 1 kHz) = 6.5 (20, 1 kHz) = 3.0 .sub.1(20 C.) = 93 mPa .Math. s k.sub.11(20 C.) = 12.9 pN k.sub.33(20 C.) = 14.8 pN V.sub.0(20 C.) = 2.35 V

(23) Mixture M-1 is divided into four parts and investigated as described below.

Comparative Examples 1.0 and 1.1

(24) Firstly, the stability of the voltage holding ratio of mixture (M-1) itself and of a further sample of this mixture to which 250 ppm of the compound TINUVIN770 have been added is determined. The resultant mixture (CM-1-1) is, like mixture M-1 itself, investigated for its stability to illumination by means of cold-cathode (CCFL)-LCD backlighting in a test cell having an alignment material for homeotropic alignment and flat ITO electrodes. To this end, corresponding test cells are exposed to the lighting for 750 hours. The voltage holding ratio is then determined in each case after 5 minutes at a temperature of 100 C. The results are summarized below in Table 1. Here, as below, six test cells are filled and investigated for each individual mixture. The values indicated are the average of the six individual values and the standard deviation () thereof, including for the case where the standard deviation is smaller than the measurement value accuracy indicated above.

Examples 1.1 and 1.2

(25) Next, 63 ppm or alternatively 250 ppm of the compound from Synthesis Example 1

(26) ##STR00210##
are added to mixture M-1, and the resultant mixtures (M-1-1 and M-1-2 respectively) are investigated for their stability, as described above. The results are shown in the following table, Table 1.

(27) The relative deviations of the voltage holding ratio values in different measurement series are typically in the range from about 3 to 4%.

(28) The drop in the voltage holding ratio (VHR) usually caused by the exposure is determined as described in the text above. Thus, a relative stabilization of S.sub.rel(750 h)=1.9 is obtained for Example 1.1 compared with the reference mixture (Comparative Example 1.0).

(29) TABLE-US-00010 TABLE 1 Stabili- c(stab.)/ VHR(t)/% S.sub.rel(t) Ex. No. Mixture zer ppm t = 0 h t = 750 h t = 750 h C1.0 1 M-1 none 0 95.4 0.3 63 0.9 1 C1.1 2 CM-1-1 T770 250 95.3 0.4 71 1.8 1.3 B1.1 3 M-1-1 I* 63 93.7 0.5 77 1.2 1.9 B1.2 4 M-1-2 I* 250 93.0 0.7 72 1.1 1.5 Notes: I*: compound from Synthesis Example 1 T770: TINUVIN770

(30) In addition, the ion densities of the four mixtures are determined. The results are summarized in the following table (Table 2).

(31) TABLE-US-00011 TABLE 2 Stabili- c(stab.)/ Ion S.sub.rel(t) Ex. No. Mixture zer ppm density/pC t = 750 h C1.0 1 M-2 none 0 159 21 1 C1.1 2 CM-1-1 T770 250 851 89 1.3 B1.1 3 M-1-1 I* 50 179 17 1.9 B1.2 4 M-1-2 I* 250 234 26 1.5 Notes: I*: compound from Synthesis Example 1 T770: TINUVIN770

(32) It is readily evident here that the compound from Synthesis Example 1, even in relatively low concentrations, clearly exhibits stabilizing properties which are clearly superior both to those of the starting mixture and also to those of the comparative mixture. In addition, the ion density is virtually unchanged compared with the undoped reference. TINUVIN770, by contrast, exhibits an ion density which is four times as high, which suggests a stronger ionic interaction with the polyimide. TINUVIN770 thus exhibits a significantly stronger interaction with the alignment material. The behavior for the compound from Synthesis Example 1 looks significantly more favorable.

(33) The compound from Synthesis Example 1 in a concentration of 63 ppm has a stabilization activity which is superior to all other stabilizers investigated here. This results in a reduction in the risk of image sticking during exposure to the backlighting.

Examples 2.1 and 2.2 and Comparative Examples 2.0 and 2.1

(34) The following mixture (M-2), which comprises 37% of compounds containing an alkenyl end group, is prepared and investigated.

(35) TABLE-US-00012 Mixture M-2 Composition Compound Concentration No. Abbreviation /% by weight 1 CY-3-O2 15.0 2 CY-3-O4 3.0 3 CCY-3-O2 6.0 4 CCY-3-O3 3.5 5 CCY-4-O2 5.0 6 CPY-2-O2 8.0 7 CPY-3-O2 8.0 8 PYP-2-3 8.0 9 PYP-2-4 6.5 10 CC-3-V 37.0 100.0 Physical properties T(N, I) = 74 C. n.sub.e(20 C., 589 nm) = 1.5927 n(20 C., 589 nm) = 0.1072 .sub.(20, 1 kHz) = 6.6 (20, 1 kHz) = 3.0 .sub.1(20 C.) = t.b.d. mPa .Math. s k.sub.11(20 C.) = 12.4 pN k.sub.33(20 C.) = 13.9 pN V.sub.0(20 C.) = 2.27 V Note: t.b.d.: to be determined

(36) Mixture M-2 is, as described in Example 1, divided into four parts, and, as described therein, two different concentrations of the compound from Synthesis Example 1 or TINUVIN770 are alternatively added, and the corresponding mixtures are investigated for their stability to illumination by means of LCD backlighting in test cells. For the mixtures which comprise the compound from Synthesis Example 1, comparably favorable results as in Example 1 are also achieved here.

Examples 3.1 and 3.2 (B3.1 and B3.2) and Comparative Examples 3.0 and 3.1 (C3.0 and C3.1)

(37) The following mixture (M-3), which comprises 40% of compounds containing an alkenyl end group, is prepared and investigated.

(38) TABLE-US-00013 Mixture M-3 Composition Compound Concentration No. Abbreviation /% by weight 1 CY-3-O2 10.0 2 PY-3-O2 10.0 3 CCY-3-O2 11.0 4 CPY-2-O2 8.5 5 CPY-3-O2 10.5 6 PYP-2-3 7.0 7 CC-3-V 33.5 8 CC-3-V1 6.5 9 CCP-3-1 3.0 100.0 Physical properties T(N, I) = 74.9 C. n.sub.e(20 C., 589 nm) = 1.5931 n(20 C., 589 nm) = 0.1081 .sub.(20, 1 kHz) = 6.5 (20, 1 kHz) = 3.0 .sub.1(20 C.) = t.b.d. mPa .Math. s k.sub.11(20 C.) = 13.0 pN k.sub.33(20 C.) = 15.9 pN V.sub.0(20 C.) = 2.43 V Note: t.b.d.: to be determined

(39) Mixture M-3 is, as described in Example 1, divided into four parts, and, as described therein, two different concentrations of the compound from Synthesis Example 1 or TINUVIN770 are alternatively added, and the corresponding mixtures are investigated in test cells for their stability to illumination by means of LCD backlighting. For the mixtures which comprise the compound from Synthesis Example 1, comparably favorable results as in Example 1 are also achieved here. These are summarized in the following two tables.

(40) TABLE-US-00014 TABLE 3 Stabili- c(stab.)/ VHR(t)/% S.sub.rel(t) Ex. No. Mixture zer ppm t = 0 h t = 1000 h t = 1000 h C3.0 1 M-3 none 0 98.0 0.3 68 2 1 C3.1 2 CM-3-1 T770 250 96.6 0.4 79 2 1.7 B3.1 3 M-3-1 I* 25 97.3 0.2 77 1 1.5 B3.2 4 M-3-2 I* 50 t.b.d. t.b.d. t.b.d. Notes: I*: compound from Synthesis Example 1 T770: TINUVIN770 t.b.d: to be determined

(41) TABLE-US-00015 TABLE 4 Stabili- c(stab.)/ Ion S.sub.rel(t) Ex. No. Mixture zer ppm density/pC t = 1000 h C3.0 1 M-3 none 0 181 25 1.0 C3.1 2 CM-3-1 T770 250 1.031 58 1.7 B3.1 3 M-3-1 I* 25 224 29 1.5 B3.2 4 M-3-2 I* 50 t.b.d. t.b.d. Notes: I*: compound from Synthesis Example 1 T770: TINUVIN770 t.b.d: to be determined

Examples 4.1 to 4.3 (B4.1-B4.3) and Comparative Examples 4.0 and 4.1 (C4.0-C4.1)

(42) The following mixture (M-4), which comprises in total slightly more than 38% of compounds containing an alkenyl end group, is prepared and investigated.

(43) TABLE-US-00016 Mixture M-4 Composition Compound Concentration No. Abbreviation /% by weight 1 CY-3-O2 15.0 2 CY-5-O2 6.5 3 CCY-3-O2 11.0 4 CPY-2-O2 5.5 5 CPY-3-O2 10.5 6 PYP-2-3 12.5 7 CC-3-V 28.5 8 CC-3-V1 10.0 9 PPGU-3-F 0.5 100.0 Physical properties T(N, I) = 74.7 C. n.sub.e(20 C., 589 nm) = 1.5923 n(20 C., 589 nm) = 0.1082 .sub.(20, 1 kHz) = 6.6 (20, 1 kHz) = 3.0 .sub.1(20 C.) = 97 mPa .Math. s k.sub.11(20 C.) = t.b.d. pN k.sub.33(20 C.) = t.b.d. pN V.sub.0(20 C.) = t.b.d. V Note: t.b.d.: to be determined

(44) Mixture M-4 is divided into a plurality of parts and investigated as described below.

(45) Next, 250 ppm of TINUVIN 770 or in each case alternatively 50 ppm of the compound from Substance Example 47

(46) ##STR00211##
50 ppm of the compound from Substance Example 48

(47) ##STR00212##
250 ppm of the compound from Substance Example 49 (Synthesis Example 6)

(48) ##STR00213##
are added to the various parts of mixture M-4, and the resultant mixtures (CM-4.1 and M-4-1 to M-4-3) are investigated for their stability, as described above. The results are shown in the following two tables.

(49) TABLE-US-00017 TABLE 5 Sta- c S.sub.rel(t) bili- (stab.)/ VHR(t)/% t = 1.000 Ex. No. Mixture zer ppm t = 0 h t = 1.000 h h C4.0 1 M-4 none 0 98.6 0.3 73.6 0.4 1.0 C4.1 2 CM-4-1 T770 250 97.3 0.1 87.4 0.5 2.5 B4.1 3 M-4-1 47* 50 97.4 0.3 87.0 0.9 2.4 B4.2 4 M-4-2 48* 50 97.7 0.3 84.3 2.0 2.0 B4.3 5 M-4-2 49* 250 98.6 0.2 80.8 2.0 1.4 Notes: 47*: compound from Substance Example 47 48*: compound from Substance Example 48 49*: compound from Substance Example 49 T770: TINUVIN770 t.b.d.: to be determined

(50) On exposure to a CCFL backlight, it is found that, for example, the compound from Substance Example 47 has virtually the same stabilizing action as TINUVIN770.

(51) TABLE-US-00018 TABLE 6 Stabili- c(stab.)/ Ion S.sub.rel(t) Ex. No. Mixture zer ppm density/pC t = 1000 h C4.0 1 M-4 none 0 87 7 1.0 C4.1 2 CM-4-1 T770 250 851 89 2.5 B4.1 3 M-4-1 47* 50 266 34 2.4 B4.2 4 M-4-2 48* 50 228 53 2.0 B4.3 5 M-4-2 49* 250 98 14 1.4 Notes: 47*: compound from Substance Example 47 48*: compound from Substance Example 48 49*: compound from Substance Example 49 T770: TINUVIN770 t.b.d.: to be determined

(52) All novel compounds investigated here exhibit significantly lower values of the ion density than TINUVIN770. A significantly lower number of ions caused by the stabilizers can thus be expected.

Examples 5.1 to 5.3 (B5.1-B5.3) and Comparative Examples 5.0 and 5.1 (C5.0-05.1)

(53) The following mixture (M-5), which comprises in total slightly more than 36% of compounds containing an alkenyl end group, is prepared and investigated.

(54) TABLE-US-00019 Mixture M-5 Composition Compound Concentration No. Abbreviation /% by weight 1 CY-3-O2 9.0 2 PY-3-O2 13.5 3 CCY-3-O1 8.0 4 CCY-3-O2 3.0 5 CCY-4-O2 3.0 6 CPY-2-O2 10.0 7 CPY-3-O2 10.0 8 CC-3-V 36.5 9 CPP-3-2 6.5 10 PPGU-3-F 0.5 100.0 Physical properties T(N, I) = 74.6 C. n.sub.e(20 C., 589 nm) = 1.5938 n(20 C., 589 nm) = 0.1082 .sub.(20, 1 kHz) = 6.9 (20, 1 kHz) = 3.2 .sub.1(20 C.) = 94 mPa .Math. s k.sub.11(20 C.) = 13.0 pN k.sub.33(20 C.) = 14.6 pN V.sub.0(20 C.) = 2.29 V

(55) Mixture M-5 is divided into a plurality of parts and investigated as described below. Next, in each case alternatively 25 ppm, 50 ppm or 100 ppm of the compound from Substance Example 1, which is also used in Example 1, are added to the various parts of mixture M-5.

(56) TABLE-US-00020 TABLE 7 Sta- VHR(t)/% S.sub.rel(t) Mix- bili- c(stab.)/ t = 1.000 t = 1.000 Ex. No. ture zer ppm t = 0 h h h C5.0 1 M-5 none 0 94 0.5 30 2 1.0 B5.1 3 M-5-1 I* 25 94 0.5 42 2 1.4 B5.1 4 M-5-2 I* 50 94 0.5 62 2 2.1 B5.2 5 M-5-2 I* 100 94 0.5 77 1 2.6 Notes: I*: compounds from Synthesis Example 1

(57) TABLE-US-00021 TABLE 8 Stabili- c(stab.)/ Ion S.sub.rel(t) Ex. No. Mixture zer ppm density/pC t = 1.000 h B5.1 3 M-5-1 I* 25 169 9 1.0 B5.2 4 M-5-2 I* 50 t.b.d. 1.4 B5.3 5 M-5-2 I* 100 t.b.d. 2.1 B5.1 3 M-5-1 I* 25 t.b.d. 2.6 Notes: I*: compound from Synthesis Example 1 t.b.d.: to be determined

(58) Mixture M-5 is prepared again and again divided into a plurality of parts and investigated as described below. Next, in each case alternatively 250 ppm TINUVIN770, 50 ppm of the compound from Synthesis Example 2 (Substance Example 4)

(59) ##STR00214##
or 50 ppm or 250 ppm of the compound from Synthesis Example 8 (Substance Example 50)

(60) ##STR00215##
are added to the various parts of mixture M-5.

(61) TABLE-US-00022 TABLE 9 Sta- c VHR(t)/% S.sub.rel(t) bili- (stab.)/ t = t = Ex. No. Mixture zer ppm t = 0 h 1.000 h 1.000 h C5.1 2 CM-5-1 T770 250 94 0.6 72 2 1.0 B5.4 6 M-5-4 II* 50 95 0.2 77 2 1.2 B5.5 7 M-5-5 VIII* 50 95 0.3 71 2 1.5 B5.6 8 M-5-6 VIII* 250 94 1.1 78 2 1.7 Notes: II*: compound from Synthesis Example 2 VIII*: compound from Synthesis Example 8 T770: TINUVIN770 t.b.d.: to be determined

(62) TABLE-US-00023 TABLE 10 Stabili- c(stab.)/ Ion S.sub.rel(t) Ex. No. Mixture zer ppm density/pC t = 500 h C5.1 2 CM-5-1 T770 V5.1 1,247 40 1.0 B5.4 6 M-5-4 II* B5.4 t.b.d. 1.2 B5.5 7 M-5-5 VIII* B5.5 t.b.d. 1.5 B5.6 8 M-5-6 VIII* B5.6 t.b.d. 1.7 Notes: II*: compound from Synthesis Example 2 VIII*: compound from Synthesis Example 8 T770: TINUVIN770 t.b.d.: to be determined

Examples 6.1 to 6.3 (B6.1-B6.3) and Comparative Examples 6.0 and 6.1 (C6.0-C6.1)

(63) The following mixture (M-6), which comprises in total 35.5% of compounds containing an alkenyl end group, is prepared and investigated.

(64) TABLE-US-00024 Mixture M-6 Composition Compound Concentration No. Abbreviation /% by weight 1 CY-3-O2 2.0 2 CCY-3-O1 5.0 3 CCY-3-O2 7.0 4 CPY-2-O2 9.0 5 CPY-3-O2 9.0 6 PY-3-O2 12.5 7 PYP-2-3 10.0 8 CC-3-V 37.5 9 CC-3-V1 8.0 100.0 Physical properties T(N, I) = 75 C. n(20 C., 589 nm) = 0.1112 (20, 1 kHz) = 2.6 .sub.1(20 C.) = 83 mPa .Math. s k.sub.11(20 C.) = 13.2 pN k.sub.33(20 C.) = 15.1 pN V.sub.0(20 C.) = 2.56 V Notes: t.b.d.: to be determined

(65) Mixture M-6 is divided into a plurality of parts and in each case 250 ppm of a different compound, namely TINUVIN770, the compound from Synthesis Example 1, the compound from Synthesis Example 2 (Substance Example 4) or the compound from Synthesis Example 8 (Substance Example 50), are added to the various parts of mixture M-6, and the respective mixtures are investigated for their stability to illumination by means of LCD backlighting in test cells.

(66) TABLE-US-00025 TABLE 11 Stabi- c(stab.)/ VHR(t)/% S.sub.rel(t) Ex. No. Mixture lizer ppm t = 0 h t = 500 h t = 500 h C6.0 2 M-6 none 0 75 1.0 51 1 1.0 B6.1 2 CM-6-1 T770 250 88 1.0 69 1 1.5 B6.1 6 M-6-1 I* 250 83 1.7 74 2 8.5 B6.2 7 M-6-2 II* 250 71 1.1 67 1 5.1 B6.3 8 M-6-3 VIII* 250 71 1.9 63 1 2.8 Notes: I*: compound from Synethesis Example 1 II*: compound from Synethesis Example 2 VIII*: compound from Synethesis Example 8 T770: TINUVIN770 t.b.d.: to be determined

(67) TABLE-US-00026 TABLE 12 Stabi- c(stab.)/ Ion S.sub.rel(t) Ex. No. Mixture lizer ppm density/pC t = 500 h C6.0 2 M-6 none 0 t.b.d. 1.0 B6.1 2 CM-6-1 T770 250 t.b.d. 1.5 B6.1 6 M-6-1 I* 250 t.b.d. 8.5 B6.2 7 M-6-2 II* 250 t.b.d. 5.1 B6.3 8 M-6-3 VIII* 250 t.b.d. 2.8 Notes: I*: compound from Synethesis Example 1 II*: compound from Synethesis Example 2 VIII*: compound from Synethesis Example 8 T770: TINUVIN770 t.b.d.: to be determined

(68) The entire disclosure[s] of all applications, patents and publications, cited herein and of corresponding German Application Nos. 10 2011 018 629.8, filed Apr. 21, 2011, and 10 2011 103 024.0, filed Jun. 1, 2011, are incorporated by reference herein.

(69) The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.